1. Field of the Invention
The present invention relates to an apparatus and method for generating numerical control information by first writing and storing, as a processing method database, changes to a processing method extracted from numerical control information and to a processing method extracted during a processing operation using numerical control information and then searching for and using a suitable processing method based on the processing method database.
2. Description of the Related Art
An operation of a numerical control machine tool can be automatically controlled by inputting numerical control information and is recently used in a wide variety of fields such as microprocessors, power electronics, and as a computer controlled machine tool (CNC machine tool) by combining with software.
Typically, numerical control information such as an NC program is constructed from a tool changing instruction, a spindle speed instruction, a cutting rate instruction, a feedrate instruction, an axis movement/interpolation instruction, and a miscellaneous function instruction, etc., and numerical control information suitable for a machine tool which is the processing control object is generated each time.
Generally, the numerical control information is automatically generated at a programming room by inputting raw material data and final component shape (or processing element for forming the final component shape) to a numerical control information generating apparatus such as a CAM and an automatic programming apparatus. More specifically, the numerical control information generating apparatus automatically determines a sequence of work elements required to complete the input processing element (or a processing element automatically identified from the input final component shape), then determines tools to be used, cutting condition, and processing operation pattern for each of the determined work elements, and finally, automatically generates a numerical control information which includes, as mentioned above, a tool changing instruction, a spindle speed instruction, a cutting rate instruction, a feedrate instruction, an axis movement/interpolation instruction, and a miscellaneous function instruction, etc., based on the determined processing method.
The above mentioned numerical control information generating apparatus generally refers to a processing method database which includes the determination rules when it determines the work elements, tools, cutting conditions, and processing operation patterns. A programmer using the numerical control information generating apparatus needs to perform some maintenance work such as continuously updating the processing method database in order to obtain a desired determination result.
The numerical control information generated at the programming room, on the other hand, is transported to the processing site and is most often corrected by a processing operator. In practice, the processing operator inputs the numerical control information given from the programming room to the CNC machine tool, adjusts (corrects and edits) the numerical control information by repeating test cuttings, completes the numerical control information to be finally used in the processing, and uses the numerical control information for processing control of the machine tool.
In a processing of a component with a small lot number, there are cases where the processing operator would not correct or edit the numerical control information, but instead, complete component processing for a desired number for the lot by correcting the cutting condition using various operation switches on the NC operation panel, such as a feedrate override switch, etc.
In order to use the contents of the corrective editing and correction manipulation that are performed by the processing operator as processing know-how of a processing engineer who actually performs the processing work for the next numerical control information generation, this knowledge must be reflected in the processing method database of the numerical control information generating apparatus in the programming room. However, this reflection of knowledge requires the programmer to specify, sort, classify, and execute the correction content each time the processing operator makes a correction. Thus, in practice, this reflection has not been performed. As a result, quality improvement of the numerical control information could not be achieved, and for each and every processing, the processing operator must repeat the corrective editing and correction operation.
When a CNC machine tool user who had been manually generating the numerical control information decides to introduce a numerical control information generating apparatus to improve efficiency, he will encounter the following difficulty.
Initial data, which is determined by the maker of the apparatus, is installed as the processing method database when the apparatus is first introduced. This initial data is usually not suited to the user""s particular processing method. Therefore, the user must sort and classify the processing knowledge that has been accumulated while he generated the numerical control information manually and customize the processing method database based on the result of the sorting and classification. This process itself requires a lot of labor and man power.
As explained above, in the conventional numerical control information generating apparatus, it was not easy to immediately reflect the correction to the numerical control information in the processing method database based on experience and knowledge of the processing operator obtained from using the CNC machine tool to perform the processing work. Also, it was not easy to newly customize the processing method database based on the processing know-how accumulated over the years by a CNC machine tool user.
The present invention is conceived to solve the above-mentioned problem and an object of the present invention is to provide an apparatus for generating suitable numerical control information by writing and storing, in a processing method database, a numerical control information corrective edited by a processing operator or a processing method extracted from numerical control information used for a long period of time, searching a suitable processing method through the processing method database when a programmer newly generates a numerical control information, and using the search result. Another object of the present invention is to provide an apparatus for generating a suitable numerical control information by writing and storing, in the processing method database, extracted operation interrupting manipulation performed by a processing operator during the processing operation through various switches on the NC manipulation panel and the processing condition that has been changed, searching for a suitable processing method through the processing method database when a programmer newly generates a numerical control information, and using the search result.
The apparatus and method according to the present invention comprise: means or a step for writing and storing a work expansion model extracted for each processing element type based on numerical control information as a work expansion database; means or a step for writing and storing a tool, a cutting condition, or a processing operation pattern for each work element type based on the numerical control information as a work method database; means or a step for specifying the processing element type; means or a step for searching through the work expansion database for the work expansion model suited to the specified processing element type; means or a step for searching though the work method database for a tool, a cutting condition, or a processing operation pattern required for processing of each of the work elements used by the searched work expansion model; and means or a step for generating numerical control information using the searched result.
According to another aspect of the present invention, measurement information measured by a measuring device is added to the work expansion model to be written and stored in the work expansion database, the means for specifying the processing element type is means capable of specifying both the processing element type and the processing precision, the means for searching the work expansion model is means for searching through the work expansion database for the work expansion model corresponding to the specified processing element type and processing precision, and the means for searching tools, cutting conditions, or processing operation patterns required for the processing is means for searching the tools, cutting conditions, or processing operation patterns corresponding to the specified processing precision.
According to another aspect of the present invention, there is provided a numerical control information generating apparatus and method having a work method database for determining a cutting condition or a processing operation pattern of a work element, for generating numerical control information based on the cutting condition or the processing operation pattern determined by using the work method database, the numerical control information generating apparatus and method comprising: means or a step for writing and storing changed cutting condition or processing operation pattern using the numerical control information as an operation interrupting manipulation history database; and means or a step for generating numerical control information giving higher priorities to the changed cutting conditions and processing operation patterns stored in the operation interrupting manipulation history database when numerical control information is generated based on the cutting conditions or the processing operation patterns determined by using the work method database.
The present invention also includes a medium in which computer programs for executing each of the steps are stored.